Drawing instrument



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DRAWING INSTRUMENT Filed Feb. 24, 1964 5 Sheets-Sheet 2 as so 9 as 98 FIG. 2

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DRAWING INSTRUMENT Filed Feb. 24, 1964 5 Sheets-Sheet .3

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INVENTOR %4 Y B 112M 1 2 1 J /ff /4 TTo Fen 15y United States Patent 3,258,843 DRAWING INSTRUMENT Gordon M. Nasser, 7421 Cunningham Ave., Highland, Calif. Filed Feb. 24, 1964, Ser. No. 346,613 Claims. (Cl. 3377) This invention relates generally to drawing instruments and particularly to devices for making it possible to draw true perspectives.

One of the main objects of the invention is to produce a drawing instrument that will produce true perspectives.

Another object of the invention is in the provision of a device that, once set for eye level and/ or point of view, will thereafter operate automatically to indicate true perspectives on the drawing.

Still another object of the invention is to produce a combined drawing instrument and device for automatically insuring absolutely true drawing perspectives.

Yet another object of the invention is to provide adjustment means for varying the vanishing points of the perspective as desired.

A further object of the invention is to provide an automatic perspective indicating device in which ratios of movement of a fixed vertical laterally movable blade are the same as a vertical movable pivot point for vanishing arms.

A still further object of the invention is to provide an automatic perspective seeking device that is applicable to a conventional drawing board and readily workable thereon.

Other objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment thereof, reference being had to the accompanying drawings, wherein:

FIGURE 1 is a plan view of the device;

FIGURE 2 is a sectional view taken on the line 22 of FIGURE 1;

FIGURE 3 is a sectional view taken on the line 33 of FIGURE 1;

FIGURE 4 is a sectional view taken on the line 44 of FIGURE 1;

FIGURE 5 is a sectional view taken on the line 55 of FIGURE 1;

FIGURE 6 is a sectional view taken on the line 66 of FIGURE 1;

FIGURE 7 is a sectional view taken on the line 77 of FIGURE 1; and

FIGURES 8, 9 and 10 are a series of schematic views, showing the device in starting position and diiferent positions of automatic perspective adjustment.

Referring to the drawings, a conventional drawing board has been referred to as D. A blade B is fixedly disposed in a vertical position on the guide 105 for lateral or side-to-side motion. Means for holding the blade B in fixed vertical position, but permitting lateral movement, is provided by an upper roller riding in a gu de slot 22 in the board D and dual rollers 24 and 26 riding in a spaced parallel overhead guide 105 attached to the board D. The roller 20 is pinned at 29 for rolling movement, and the rollers 24 and 26 are similarly attached at 27 and 28 to a plate extending on either side of the blade at 32 and 34 respectively. An elevated, horizontally disposed rack bar 36 is attached to the overhead guide or forms an integral part of the upper edge of the board D.

The blade B is gear-connected in a desired ratio in a manner now to be described, but this ratio may be varied as desired. A drawn wire pinion 38 rotatably supported in a bearing block 48 attached to the blade B extends the length of said blade and is rotatably supported and secured in a manner as desired in a similar block bearing 42 attached to the lower or open end of the blade B. A gear train controlling the movement of the wire pinion includes gear 46, a second gear 47, and a third gear 48 secured to the upper end of said wire pinion. Lateral or sidewise movement of the fixed vertical blade thus operates to rotate the pinion 38 in reverse direction.

The blade B is gear-connected in a desired ratio in a manner as indicated at 50 and 52. A carriage generally referred to as C has spread recessed feet 54 and 56 slidably gripping the ridges or guides 50 and 52, respectively. The carriage C is capable of manual movement vertically along the blade B just as said blade is movable across the board D as desired. The carriage C is apertured at 58 and 68 to slidably support a horizontally disposed rack bar 62. As shown in FIGURE 2, the drawn wire pinion 38 meshes with the rack bar 62 and moves it from side to side depending upon the movement of the blade B. It is apparent, however, that movement of the blade B in either direction results in reverse directional movement of the rack bar 62. It is desirable, but not absolutely necessary, that the rack bar be calibrated at 64 as will be later described.

A pair of slidable blocks 66 and 68 on the rack bar 62 adjustably receive a pair of calibrated vertical arms 70 and 72, respectively. Releasable adjustable members 74 of any character may be used. Slidable guide blocks 76 and 78 pivotally connected at 79 to the upper ends of arms 70 and 72, respectively, engage and are sustained in grooves 80 and 82, respectively, formed in dual perspective or vanishing arms 84 and 86, respectively. The inner ends of the vanishing arms 84 and 86 have a single pivoted connection 88 in a block 90 guided in a slidable manner in an elongated vertical recess 92 in the blade B. The pivot 88 is in the exact center of the blade, but need not necessarily be so positioned.

Movement of the pivot 88 by manual vertical movement of the carriage C is accomplished by the following mechanism. A rack 94 is attached to the blade rib 52 and the foot 56 of the carriage C slides thereover. An inner projection 96 on the carriage C pivotally supports thereunder a large gear 98 that is attached to a second, smaller gear 100. The gear or pinion 100 meshes with the teeth on the smaller rack bar 102 fixed at 104 to the slidable pivot block 90. Before explaining the detailed operation of the device, it is considered advisable to state that the mechanism descnbed for creating the relative movements of the parts may be changed without departing from the spirit of the invention. It is absolutely essential that the ratio or proportion of the movement transmitted to the rack bar 62 by movement of the blade B, be the same or in the same proportion as that given the vanishing arms pivot point by manual movement of the carriage C.

Although the device is a drawing instrument and is usable as the same, nevertheless, the primary object is to provide mechanism that will automatically indicate true perspective lines once the device is set for eye level and point of view of drawing. The device eliminates any possible distortion in perspective drawings. The device is adjustable to the extent that the distance of vanishing points may be set from points on the board or drawing, to points many feet from the board. However, this will become apparent when the operation of the device is understood.

The mechanism as described results in movement of the rack bar 62 when the blade B is moved to one side or the other. Actually, if the blade B is moved to the right, the drawn Wire pinion 38 will move the rack bar in the reverse manner so that it extends further to the I the pivot point 88 for the vanishing or perspective arms will be moved in exactly the same ratio proportion of movement as the rack bar 62 induced by movement of the blade B. If is essential that this movement be in the same proportion throughout. If the ratio should be changed for one, it must be changed for the other. With this understanding, it is possible to proceed to the actual use of the device.

Any point in the drawing, as far as eye level and point of view, may be taken. In FIGURE 8 of the drawings, an eye level point of view X has been chosen. As shown in FIGURE 8, the blade B has been moved to the right so that the point of view X coincides with the exact center thereof. This movement has resulted in the rack bar 62 protruding further in the reverse manner to the left. The vanishing or perspective arms 84 and 86 are now set, or have been previously set, in a horizontal position so that the pivot point thereof coincides with the chosen eye level or point of view. Movement of the perspective arms may be acomplished by adjustment of the vertical arms 70 and 72. Although the arms 70 and 72 show calibrations, the amount of vertical adjustment is arbitrary, as long as it is the same for both. Under some drawing conditions their positions might be varied, but not for this first description. The arms 70 and 72 are then adjusted on the rack 62 so that they are equidistant from the center of the blade B at eye level. This actual setting as a start for use is shown in FIGURE 8.

The lateral setting of the arms 70 and 72 on the rack is determined by the draftsman and indicates how far out he desires the vanishing point of the perspective to be. He can set the device as he desires, and the calibrations are particularly useful in case he makes repetitive drawings and has to go back for the setting of a particular drawing.

Once the setting of the instrument has been made, irrespective of the viewpoint, it works automatically thereafter to indicate absolutely true perspective. Vertical and horizontal lines may be drawn on the blade B and rack bar 62 by manual movement thereof, but the automatic movement of the vanishing arms 70 and 72 to a position of true perspective never changes, as shown in FIGURES 9 and 10.

The device as described eliminates alldefects and limitations of previous devices. It makes possible perspective drawings in detailed accuracy and magnitude. The instrument may be used for detail drawings or large panoramic views, depending upon the size of the instrument. The device may be set and reset for different perspective views in the same drawing by use of the calibrations on the rack bar 62. Vanishing points may be set from points on the board or drawing, to points many feet from the board by means of the adjustments on the calibrated scales or by changing the operating gear ratios as long as the two remain the same or equal. The instrument makes possible the drawing of finely divided mathematically correct perspective lines when vanishing points in the drawing are extended to great distances from the board.

While I have shown and described in considerable detail what I believe to be the preferred form of my invention, it will be understood by those skilled in the art that various changes may be made in the shape and arrangement of the several parts without departing from the broad scope of the invention as defined in the following claims.

I claim:

1. A drawing instrument for automatically indicating true perspective lines from any viewpoint on a drawing board, comprising:

a blade movable in fixed vertical position laterally across said board;

a block movable vertically in said blade;

a pair of vanishing arms pivoted at their inner ends on said block;

a carriage slidable vertically on said blade;

a bar horizontally supported on said carriage;

connecting means between said arms and said bar adjustable vertically and horizontally;

mechanism for transmitting relative proportional reverse movement between said blade and said bar; and

mechanism actuated by movement of said carriage for transmitting the same proportional movement to the block sustaining the pivoted inner ends of said vanishing arms.

2. A device of the class described, comprising:

a blade movable in fixed vertical position laterally across said board;

a block movable vertically on said blade;

a pair of vanishing arms pivoted at their inner ends to the block for vertical movement;

a bar horizontally supported and vertically movable on said blade adjustable vertically and horizontal- 3/;

connections between said arms and said bar;

mechanism induced by lateral actuation of said blade for reversing the movement of said bar; and

mechanism controlling the vertical movement of the vanishing arms pivoted to the block operating in the same proportional manner.

3. A device of the class described, comprising:

a drawing board;

a blade movable laterally thereon in a vertical position;

a pair of vanishing arms pivotally connected at their inner ends for vertical movement on said blade;

a horizontally disposed bar actuated horizontally on said blade having connections with the outer ends of said arms; and

means for creating equal proportional movement between said arms and said bar whereby accurate perspectives are automatically indicated.

4. A drawing instrument for automatically indicating true perspective lines from any viewpoint on a drawing board or drawing, comprising:

a blade movable in fixed vertical position laterally across said board;

a pair of vanishing arms on either side of said blade pivoted centrally thereof and vertically movable thereon, and so attached thereto that their drawing edges always point inwardly to the central point and their outer ends to a predetermined vanishing point;

a horizontally disposed bar vertically slidable on said blade and actuated in a reverse direction thereto; and

connecting mechanism between said bar and said arms whereby relative movement is in equal proportions.

5. A device as set forth in claim 4 in which said horizontal bar is supported in a carriage manually vertically movable on said blade whereby reverse movement of said bar varies the angular adjustment of said arms in equal ratio to their vertical positioning.

References Cited by the Examiner UNITED STATES PATENTS 2,419,725 4/1947 Nosser 33-77 2,590,252 3/1952 Hurst et al. 3377 3,107,430 10/1963 Weeks 33-77 LEONARD FORMAN, Primary Examiner.

ISAAC LISANN, Examiner.

H. N. HAROIAN, Assistant Examiner. 

1. A DRAWING INSTRUMENT FOR AUTOMATICALLY INDICATING TRUE PERSPECTIVE LINES FROM ANY VIEWPOINT ON A DRAWING BOARD, COMPRISING: A BLADE MOVABLE IN FIXED VERTICAL POSITION LATERALLY ACORSS SAID BOARD; A BLOCK MOVABLE VERTICALLY IN SAID BLADE; A PAIR OF VANISHING ARMS PIVOTED AT THEIR INNER ENDS ON SAID BLOCK; A CARRIAGE SLIDABLE VERTICALLY ON SAID BLADE; A BAR HORIZONTALLY SUPPORTED ON SAID CARRIAGE; CONNECTING MEANS BETWEEN SAID ARMS AND SAID BAR ADJUSTABLE VERTICALLY AND HORIZONTALLY; MECHANISM FOR TRANSMITTING RELATIVE PROPORTIONAL REVERSE MOVEMENT BETWEEN SAID BLADE AND SAID BAR; AND MECHANISM ACTUATED BY MOVEMENT OF SAID CARRIAGE FOR TRANSMITTING THE SAME PROPORTIONAL MOVEMENT TO THE BLOCK SUSTAINING THE PIVOTED INNER ENDS OF SAID VANISHING ARMS. 